2788-28-5Relevant articles and documents
Preparation method for synthesizing L-carnitine by using R-(-)-epichlorohydrin as starting material
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Paragraph 0078-0093, (2019/11/12)
The invention discloses a preparation method for synthesizing L-carnitine by using R-(-)-epichlorohydrin as a starting material, and belongs to the field of medicinal chemistry. The method comprises the steps: using R-(-)-epoxychlorohydrin and hydrocyanic acid as starting materials, performing a reaction for synthesis of R-4-chloro-3-hydroxybutyronitrile under the action of a basic catalyst, thensynthesizing L-carnitine hydrochloride through two routes, purifying the L-carnitine hydrochloride prepared through the two routes further through resin so as to remove chloride ions, and preparing the final product L-carnitine. The two process routes are simple, the reaction conditions are mild, the operation is simple and feasible, and industrial production is convenient; the whole process is green and environmentally friendly, the reaction yield is high, three waste is little, no sodium cyanide is used, and no solid waste sodium salt is generated; and the hydrolysis by-product ammonium chloride has good quality, and can be sold as a by-product, and great economic benefits and market competitiveness are achieved.
Novel method for preparing L-carnitine
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Paragraph 0019; 0020; 0021, (2017/08/27)
The invention discloses a novel method for preparing L-carnitine and belongs to the technical field of medication chemistry. The method disclosed by the invention comprises the following steps: reacting quinine I and trimethylchlorosilane, thereby obtaining a quinine derivative II; reacting the quinine derivative II with racemic epoxy chloropropane, thereby obtaining quinine derivative quaternary ammonium salt III; reacting the quinine derivative quaternary ammonium salt III with a cyanide inorganic salt, and performing chiral ring opening to generate (R)-2-hydroxynitrile quaternary ammonium salt IV; carrying out an ion exchange reaction between the (R)-2-hydroxynitrile quaternary ammonium salt IV and trimethylamine, thereby obtaining (R)-2-hydroxynitrile trimethylamine salt, performing acidic hydrolysis, and performing ion exchange desalination, thereby obtaining the L-carnitine. The method provided by the invention is simple and feasible, the yield is greatly improved, and residues of heavy metal ions are avoided.
A PREPARATION METHOD OF HIGH-PURITY L-CARNITINE
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Page/Page column 8, (2011/09/15)
The present invention relate to a preparation method of high-purity L-carnitine which belongs to an important technique of qulity control in different steps of chiral medicine production. The method comprises the following steps of :monitoring the content of the L-isomer impurity in chiral material S-epichlorohydrin by gas chromatography and chiral cilumn and controlling the content of the L-isomer impurity in chiral raw material in the definite range; monitoring and controlling the specific optical rotation of the chiral intermediate L-3-chloro-2-hydroxy-N,N,N-trimethyl-propanaminium in the definite ranges using a polarimeter; monitoring the content of the R-isomer in the intermediate L-3-cyano-2-hydroxy-N,N,N-trimethyl-propanaminium using derivation agent (+)α-methyl-6-methoxy-2-naphthaleneaceyl chloride by HPLC and controlling the content of the isomer in the intermediate in the definite range; and measuring the final product L-carnitine using derviation agent (+)α-methyl-6-methoxy-2-naphthaleneaceyl chloride by HPLC. This method gives the high-purity L-carnitine in which the content of L-isomer may be more than 97% and that of R-isomer less than 2%.